Don't import maybetail (#132)

* move maybetail to this package

* remove maybetail

Author: jishnub

src/BlockBandedMatrices.jl

@@ -6,7 +6,7 @@ import Base: getindex, setindex!, checkbounds, @propagate_inbounds, convert,
                         +, *, -, /, \, strides, zeros, size,
                         unsafe_convert, fill!, length, first, last,
                         eltype, getindex, to_indices, to_index,
-                        reindex, _maybetail, tail, @_propagate_inbounds_meta,
+                        reindex, tail, @_propagate_inbounds_meta,
                         ==, axes, copy, copyto!, similar, OneTo
 
 import Base.Broadcast: BroadcastStyle, AbstractArrayStyle, DefaultArrayStyle, Broadcasted, broadcasted,